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Re: fixing regex collations [Was: Re: [Fwd: Comments on SPARQL from the XML Query and the XSL WGs]]

From: Eric Prud'hommeaux <eric@w3.org>
Date: Sat, 19 Nov 2005 11:44:58 -0500
To: Dan Connolly <connolly@w3.org>
Cc: "Seaborne, Andy" <andy.seaborne@hp.com>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
Message-ID: <20051119164458.GH30801@w3.org>
On Fri, Nov 18, 2005 at 12:22:19PM -0600, Dan Connolly wrote:
> 
> On Fri, 2005-11-18 at 12:45 -0500, Eric Prud'hommeaux wrote:
> > On Fri, Nov 18, 2005 at 06:37:52AM -0500, Eric Prud'hommeaux wrote:
> > > On Thu, Nov 17, 2005 at 01:10:44PM +0000, Seaborne, Andy wrote:
> > > > -------- Original Message --------
> > > >   > From: Ashok Malhotra <>
> > > >   > Date: 13 September 2005 16:28
> > > >   >
> > > >   > Notes on SPARQL Query Language for RDF
> > > >   > Last Call Draft July 21, 2005
> > > >   > ...
> > > >   > 6. String comparison is defined only using the code point collation.
> > > >   > Other collations are not supported.  This may be a significant
> > > >   > limitation.
> > > > 
> > > > Code point collation is always required.  Access to other collections can be
> > > > done through a custom function.
> > > 
> > > @@needs work here -- we say nothing about default vs user-supplied
> > > collations.
> > 
> > XPath's fn:matches
> >   http://www.w3.org/TR/xpath-functions/#func-matches
> > now has this exciting thing to say about collations:
> > [[
> > Note:
> > 
> > Regular expression matching is defined on the basis of Unicode code
> > points; it takes no account of collations.
> > ]]
> > 
> > which means we have no functions that require collations. The sentence
> > [[
> > The collation is defined in section 7.3.1 Collations.
> > ]]
> > needs to go away. I don't think we need to repeat the note.
> > 
> > Do I need a vote on this?
> 
> If so, we can do it after publication.
> 
> I haven't studied the details.
> 
> >  or can I strike it before the publication?

I think it never made sense. Going back at least as far as
  http://www.w3.org/TR/2003/WD-xpath-functions-20031112/#func-matches
we can see that note.
[[
Note:

Regular expression matching is defined on the basis of Unicode
code-points; it takes no account of collations.
]]

I thought I saw it listed in a table with "A collation may
be specified", but I can't find that text again so I have
no confidence that I ever saw it. It seems unlikely to me
that anyone voted for regex with some expectation that it
would use collations. Not impossible, just onlikely. A test
case that distinguishes them:

  _:a foaf:givenName "Björn".

  ASK { _:a foaf:givenName "Bjoern" }

would fail now, could have been concieved to pass before.
-- 
-eric

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Received on Saturday, 19 November 2005 16:45:01 GMT

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